/ncbitax2lin

Convert NCBI taxonomy dump into lineages

Primary LanguagePythonMIT LicenseMIT

NCBItax2lin

Convert NCBI taxonomy dump (taxdump, ftp://ftp.ncbi.nlm.nih.gov/pub/taxonomy/) into lineages. An example for human is like

tax_id superkingdom phylum class order family genus species family1 forma genus1 infraclass infraorder kingdom no rank no rank1 no rank10 no rank11 no rank12 no rank13 no rank14 no rank15 no rank16 no rank17 no rank18 no rank19 no rank2 no rank20 no rank21 no rank22 no rank3 no rank4 no rank5 no rank6 no rank7 no rank8 no rank9 parvorder species group species subgroup species1 subclass subfamily subgenus subkingdom suborder subphylum subspecies subtribe superclass superfamily superorder superorder1 superphylum tribe varietas
9606 Eukaryota Chordata Mammalia Primates Hominidae Homo Homo sapiens Simiiformes Metazoa cellular organisms Opisthokonta Dipnotetrapodomorpha Tetrapoda Amniota Theria Eutheria Boreoeutheria Eumetazoa Bilateria Deuterostomia Vertebrata Gnathostomata Teleostomi Euteleostomi Sarcopterygii Catarrhini Homininae Haplorrhini Craniata Hominoidea Euarchontoglires

Download lineages

All pre-converted lineages are hosted on ncbitax2lin-lineages, a GitLab repo, which allows pushing larger files without Git LFS and a bigger repo size limit.

Regenerate the lineages yourself

Regeneration is straightforward, but it may incur quite a bit of memory (~20 GB). I generated lineages.csv.gz on a machine with 32 GB memory. Pull request on refactoring to a lower memory usage is welcome. It's mainly about this line, where the pool.map takes places.

If you really need an updated version but without the hardware resources, you could also notify me on github, and I will update it for you.

Install

git clone git@github.com:zyxue/ncbitax2lin.git
cd ncbitax2lin/

Set up a virtual environment

Currently, it only works with python2.7, and needs pandas, so make sure you are in a proper virtual environment. If you have already these had one available, just use that one.

Otherwise, you can create a new one with miniconda/anaconda (recommended),

conda create -y -p venv/ --file env-conda.txt
# or effectively the same
# conda create -y -p venv python=2 pandas
source activate venv/

or with virtualenv + pip

virtualenv venv/
source venv/bin/activate
pip install -r env-pip.txt

Regenerate

Then run the following, this will download the latest taxdump from NCBI, and run the scripts to regenerate all latest lineages from it

make

FAQ

Q: I have a large number of sequences with their corresponding accession numbers from NCBI, how to get their lineages?

A: First, you need to map accession numbers (GI is deprecated) to tax IDs based on nucl_*accession2taxid.gz files from ftp://ftp.ncbi.nih.gov/pub/taxonomy/accession2taxid/. Secondly, you can trace a sequence's whole lineage based on its tax ID. The tax-id-to-lineage mapping is what NCBItax2lin generates for you, and it is available on ncbitax2lin-lineages.

Note on taxdump.tar.gz.md5

It appears that NCBI periodically regenerates taxdump.tar.gz and taxdump.tar.gz.md5 even when its content is still the same. I am not sure how their regeneration works, but taxdump.tar.gz.md5 will differ simply because of a different timestamp.